In Johnson v. United States (1948), the U.S. Supreme Court held that odor alone could not justify a search without a warrant; however, many warrantless searches and seizures stemming from the perception of odors have been upheld. In some cases, the odor provided probable cause to arrest for possession of contraband which in turn provided justification for the search. The Fourth Circuit Court has analogized the emanation of odor to the sense of sight, so as to fall within the existing 'plain view' doctrine, which permits seizures, and possibly searches, without warrants. Although the U.S. Supreme Court has permitted warrantless seizures of items in 'plain view' and has recognized that the contents of containers which can be inferred from external indications also fall within 'plain view,' it has yet to adopt categorically the 'plain smell' analogy. Apparently, the Court favors moving in this direction. If adopted, the 'plain smell' rule will likely encourage more searches and seizures without warrants than a literal reading of 'Johnson' apparently allows. 240 footnotes.